Cover your bases: If you will have access to your new place before Jan 5, or at least the mailbox at your new place, call USCIS and update your address. Also, if possible, place your name inside the mailbox of your new place. It is most likely that the card will not arrive before Jan 5 anyway, with Tuesday being a holiday and all of that. Also keep a spare key to the mailbox of your old place, and inform the postal delivery person of your old place that you are expecting an important document from the Department of Homeland Security. This happened to me, and because I talk to the postman at my old place before I left, he forwarded an approval notice to my new address (even though he wasn't supposed to). So update your mailing address ASAP but try to have access to both mailboxes as long as you can.